1 |
|
|
/* $OpenBSD: kexecdh.c,v 1.6 2015/01/19 20:16:15 markus Exp $ */ |
2 |
|
|
/* |
3 |
|
|
* Copyright (c) 2001 Markus Friedl. All rights reserved. |
4 |
|
|
* Copyright (c) 2010 Damien Miller. All rights reserved. |
5 |
|
|
* |
6 |
|
|
* Redistribution and use in source and binary forms, with or without |
7 |
|
|
* modification, are permitted provided that the following conditions |
8 |
|
|
* are met: |
9 |
|
|
* 1. Redistributions of source code must retain the above copyright |
10 |
|
|
* notice, this list of conditions and the following disclaimer. |
11 |
|
|
* 2. Redistributions in binary form must reproduce the above copyright |
12 |
|
|
* notice, this list of conditions and the following disclaimer in the |
13 |
|
|
* documentation and/or other materials provided with the distribution. |
14 |
|
|
* |
15 |
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
16 |
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
17 |
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
18 |
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
19 |
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
20 |
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
21 |
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
22 |
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
23 |
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
24 |
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
25 |
|
|
*/ |
26 |
|
|
|
27 |
|
|
#include <sys/types.h> |
28 |
|
|
|
29 |
|
|
#include <signal.h> |
30 |
|
|
#include <string.h> |
31 |
|
|
|
32 |
|
|
#include <openssl/bn.h> |
33 |
|
|
#include <openssl/evp.h> |
34 |
|
|
#include <openssl/ec.h> |
35 |
|
|
#include <openssl/ecdh.h> |
36 |
|
|
|
37 |
|
|
#include "ssh2.h" |
38 |
|
|
#include "sshkey.h" |
39 |
|
|
#include "cipher.h" |
40 |
|
|
#include "kex.h" |
41 |
|
|
#include "sshbuf.h" |
42 |
|
|
#include "digest.h" |
43 |
|
|
#include "ssherr.h" |
44 |
|
|
|
45 |
|
|
int |
46 |
|
|
kex_ecdh_hash( |
47 |
|
|
int hash_alg, |
48 |
|
|
const EC_GROUP *ec_group, |
49 |
|
|
const char *client_version_string, |
50 |
|
|
const char *server_version_string, |
51 |
|
|
const u_char *ckexinit, size_t ckexinitlen, |
52 |
|
|
const u_char *skexinit, size_t skexinitlen, |
53 |
|
|
const u_char *serverhostkeyblob, size_t sbloblen, |
54 |
|
|
const EC_POINT *client_dh_pub, |
55 |
|
|
const EC_POINT *server_dh_pub, |
56 |
|
|
const BIGNUM *shared_secret, |
57 |
|
|
u_char *hash, size_t *hashlen) |
58 |
|
|
{ |
59 |
|
|
struct sshbuf *b; |
60 |
|
|
int r; |
61 |
|
|
|
62 |
|
|
if (*hashlen < ssh_digest_bytes(hash_alg)) |
63 |
|
|
return SSH_ERR_INVALID_ARGUMENT; |
64 |
|
|
if ((b = sshbuf_new()) == NULL) |
65 |
|
|
return SSH_ERR_ALLOC_FAIL; |
66 |
|
|
if ((r = sshbuf_put_cstring(b, client_version_string)) != 0 || |
67 |
|
|
(r = sshbuf_put_cstring(b, server_version_string)) != 0 || |
68 |
|
|
/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ |
69 |
|
|
(r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 || |
70 |
|
|
(r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || |
71 |
|
|
(r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 || |
72 |
|
|
(r = sshbuf_put_u32(b, skexinitlen+1)) != 0 || |
73 |
|
|
(r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || |
74 |
|
|
(r = sshbuf_put(b, skexinit, skexinitlen)) != 0 || |
75 |
|
|
(r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 || |
76 |
|
|
(r = sshbuf_put_ec(b, client_dh_pub, ec_group)) != 0 || |
77 |
|
|
(r = sshbuf_put_ec(b, server_dh_pub, ec_group)) != 0 || |
78 |
|
|
(r = sshbuf_put_bignum2(b, shared_secret)) != 0) { |
79 |
|
|
sshbuf_free(b); |
80 |
|
|
return r; |
81 |
|
|
} |
82 |
|
|
#ifdef DEBUG_KEX |
83 |
|
|
sshbuf_dump(b, stderr); |
84 |
|
|
#endif |
85 |
|
|
if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) { |
86 |
|
|
sshbuf_free(b); |
87 |
|
|
return SSH_ERR_LIBCRYPTO_ERROR; |
88 |
|
|
} |
89 |
|
|
sshbuf_free(b); |
90 |
|
|
*hashlen = ssh_digest_bytes(hash_alg); |
91 |
|
|
#ifdef DEBUG_KEX |
92 |
|
|
dump_digest("hash", hash, *hashlen); |
93 |
|
|
#endif |
94 |
|
|
return 0; |
95 |
|
|
} |